code: def _find_duplicate(strs):
      str_set = set()
      for s in strs:
          if s in str_set:
              return s
          else:
              str_set.add(s)
      return None
  
file_path: mxnet/python/mxnet/numpy_dispatch_protocol.py
imports: import functools
  import numpy
  from .None import numpy
  from .numpy.multiarray import _NUMPY_ARRAY_FUNCTION_DICT, _NUMPY_ARRAY_UFUNC_DICT
label_desc: Use image node_id 1 for calling a global function with example usage: _find_duplicate(strs) and returns: None, s